1. Field of the Invention
The invention relates to a spring-force terminal connection for electrical conductors with a busbar section and a bent leaf spring, which has a bearing limb, which is supported on the busbar section, a spring bend section, which adjoins the bearing limb, and a clamping limb, which adjoins the spring bend section, for fixedly clamping a conductor to the busbar section.
2. Background Description
The invention furthermore relates to an electrical terminal with at least one such spring-force terminal connection, which is inserted into an insulating housing of the electrical terminal.
DE 197 11 051 A1 discloses a connecting terminal for electrical conductors, with a spring-force terminal connection, which has a bent clamping spring formed from spring sheet steel with bearing limbs, which are connected to one another via a spring bend, and clamping limbs and a busbar, which is inserted into the clamping limb and bears against the bearing limb. A conductor insertion channel, which extends from the rear spring bend of the clamping spring along the bearing limb and the busbar, is provided in the insulating housing of the terminal.
Another embodiment of screwless connection terminals is described in DE 30 19 149 C2. In this case, the end of a bearing limb, which is positioned at an angle, of a bent clamping spring rests on a conductor end by means of spring force, which conductor end has been inserted through a conductor insertion channel into a free cavity.
DE 102 39 273 A1 discloses a spring-force terminal connection for an electrical conductor, in which the clamping limb end of a leaf spring dips into a rectangular material passage in a busbar section in such a way that the clamping limb end with a hole collar inner wall face of the material passage forms a clamping point for the electrical conductor. The bearing limb is supported on that side of the material passage which is opposite the clamping point. In this case, too, the leaf spring is provided with a U-shaped spring bend section.
As a result of the positioning of the conductor insertion channel known, for example, from DE 197 11 051 A1 with a substantial part of its length below the bearing limb of the clamping spring, a reduction in the physical height of the terminal component part in the direction of extent of the conductor insertion channel is already achieved.
Against this background, the present invention is based on the object of further reducing the physical width of clamping component parts in the direction of the spring excursion of the clamping spring.
The object is achieved by the spring-force terminal connection of the type mentioned at the outset by virtue of the fact that, in the spring bend section, those parts of the leaf spring which merge with the bearing limb and the clamping limb run at least partially parallel to one another and bear against one another.
In contrast to the previously known leaf springs bent in the form of a U in which the spring bend section has a considerable radius, with the spring-force terminal connection according to the invention the distance between those parts of the spring bend section which run parallel to one another and therefore the radius of the spring bend is reduced to a maximum extent, with the result that these two parts, which merge with the bearing limb and the clamping limb, of the spring bend section bear at least partially against one another. This means that the minimum physical width predetermined with respect to one another by the radius of the spring bend in the direction of the spring excursion of a clamping component part can be reduced.
The spring bend section with a reduced radial extent can preferably be realized by virtue of the fact that the leaf spring is folded over in the spring bend section, with the result that those parts of the leaf spring which bear against one another are connected to one another in the spring bend section via a 180° bend in the leaf spring. The leaf spring can therefore be produced from spring sheet steel which is folded over by means of a suitable shaping process.
As an alternative to this, however, the leaf spring can also be produced from two parts of spring sheet steel. In this case, the leaf spring is formed from a first part, which contains the bearing limb, and a separate second part, which contains the clamping limb. These two separate parts are then connected to one another so as to form the bent integral leaf spring at the spring bend sections, which run parallel to one another, of the two parts. In order to provide a spring excursion which is as great as possible, the connection should take place at the ends of the parallel spring bend sections.
Those parts of the leaf spring which bear against one another in the spring bend section can be connected to one another by means of riveting, welding, adhesive bonding or an interlocking connection.
The spring-force terminal connection can be configured, for example in design terms, in the manner known from DE 197 11 051 A1. In this case, the clamping limb of the leaf spring has a cutout and is bent back towards the bearing limb in such a way that the busbar section, which bears against the bearing limb, extends away from the bearing limb through the cutout, and the limit of the cutout at the end of the clamping limb together with the busbar section forms a clamping point for a conductor, which is plugged from the spring bend in the direction of the cutout and through the cutout.
However, it is conceivable for the spring-force terminal connection to be configured so as to have the design known in principle from DE 102 39 273 A1. In this case, the busbar section is manufactured from a flat material and has a conductor plug-through opening. The leaf spring dips into the conductor plug-through opening and forms, with the material passage of the conductor plug-through opening, a clamping point by virtue of the clamping limb of the leaf spring in the rest position, in which there is no conductor inserted into the conductor plug-through opening, bearing in sprung fashion against a clamping section at the conductor plug-through opening. In this case, the bearing limb preferably likewise extends into the conductor plug-through opening and is supported on that inner edge of the conductor plug-through opening which is opposite the clamping point. However, it is also conceivable for the bearing limb to be fastened in another way on the busbar section.